1. Field
The described technology generally relates to a display substrate and a method of manufacturing the display substrate, more particularly, to a display substrate used for a liquid crystal display (LCD) apparatus and a method of manufacturing the display substrate.
2. Description of the Related Technology
Generally, an LCD substrate includes a first display substrate including a thin-film transistor (TFT) for driving a pixel, a second display substrate facing the first display substrate, and a liquid crystal layer interposed between the first and second display substrates. A voltage is usually applied to the liquid crystal layer to control light transmittance so that the LCD substrate displays an image. An alignment layer is often formed on each of the first and second display substrates to adjust an initial alignment of liquid crystal molecules of the liquid crystal layer. The liquid crystal molecules are interposed between the alignment layers facing each other.
A material used for the alignment layer generally includes a polyamic acid based compound for improving strength of the alignment layer or a polyimide based compound having a high voltage holding rate. These may be used alone or a combination thereof. A raw material for the alignment layer may be coated on a substrate by an ink jetting process or a rolling process to form the alignment layer. Alternatively, the alignment layer may be formed by additionally rubbing a surface of the coated raw material on the substrate.
However, when the alignment layer is formed on each of the first and second display substrates of the LCD substrate having a quadrilateral shape when viewed in a plane, generally a repulsive force between a raw material layer and patterns formed under the raw material layer is generated due to chemical characteristics of the raw material although the raw material is uniformly coated on each of the first and second display substrates. Thus, corner portions of the raw material layer are typically rolled toward an inside of each of the first and second display substrates. Accordingly, the alignment layer is often not uniformly formed on each of the first and second display substrates. Generally, the alignment layer is not easily formed on a region in which the raw material layer is not formed, and thus the liquid crystal molecules might not be controlled to decrease a display quality. The above information disclosed in this Background section is only intended to facilitate the understanding of the background of the described technology and therefore it may contain information that does not constitute the prior art that is already known in this country to a person of ordinary skill in the art.